Automatic self-feeding carburetor



Sept. 15, 1925. 1,553,453'

H. E. MARSH AUTOMATIQ SELF FEEDING CA RBURETOR Filed March 10, 1925 6 5' I 4a INVENETOR 54 ATTORNEY Patented Sept. 15, 1925.

UNITED STATES HOWARD E. MARSH, OF LOMPOG, CALIFORNIA.

AUTOMATIC SELF-FEEDING GARBURETOR.

Application filed March 10, 1925. Serial No. 14,355.

To all whom it may concemil:

Be it known that I, 'HowAnn E. MARSH, a citizen of the United States, residing at Lompoc, in the county of Santa Barbara andState of California, have invented certain new and useful Improvements in Automatic Self-Feeding Carburetors, of which the following is a specification.

The present invention relates to carburetors for internal combustion engines and the like.

The principal object of the invention is to provide a carburetor in which is incorporated means, actuated by the reduced pressure or suction at the engine intake, for automatically feeding the liquid fuel from a lower level. It is therefore especially adapted for use in automobiles, in which the fuel tank is ordinarily located in a low position at the rear of the body. In such use it combines in one structure the functions of two separate commonly employed devices, the carburetor and the so-called vacuum tank, and by so doing eliminates the duplication of certain parts necessary to the operation of both such devices. A further object of the invention is to provide a vacuum or suction fuel feed device which may be added, without great expenses, to any suitable form of standard carburetorin present use.

A still further object of the invention is to provide an eflicient and inexpensive means for heating either the liquid fuel, or the mixture of vaporized fuel and air, or both, to assist the vaporization of the fuel and its proper admixture with the air. Other objects and advantages of the invention will become apparent from the following description of a preferred embodiment thereof. It should be understood, however,

that the form and construction herein illus trated and described may be varied, within the limits of the claims hereto appended, without departing from the spirit of the invention as set forth in said claims.

WVith this in view my invention will now be fully described with reference to the accompanying drawings, wherein:

Fig. 1 is: a vertical section of a carburetor embodying a preferred form of my said invention. V

Fig. 2 is a plan view thereof,

Fig. 3 is a detailed side elevation of the auxiliary air inlet shutter.

In the drawings, the reference numeral 1 designates a carburetor body, having a preferably integral float chamber or liquid fuel reservoir 2, an air inlet 3, and an outlet at 1 adapted for connection with the intake pipe or manifold, not shown, of an engine. Between said air inlet and said manifold connection is the mixing chamber 5, which is preferably formed within a removable Venturi tube 6, the latter being secured in the body 1 by any convenient means, as for example a screw thread shown at 7 The usual butterfly choke valve is shown in the air inlet at 8, to enable an over-rich mixture to be formed to facilitate starting the engine, and the usual butterfly throttle valve 9 is provided above the mixing chamber5 to regulate the quantity of gaseous fuel supplied to said engine.

The float chamber'2 contains a float 10 adapted to rise and fall with the liquid contained in said chamber, and said float operates a valve stem 11 through levers 12 fulcrumed at 13, said stem moving in the opposite direction to said float. The lower end of the stem 11 forms a needle valve14. to control the admission of liquid fuel to the chamber 2 from a supply pipe 15 in accordance with amount of liquid contained within said chamber.

The liquid fuel passes out of the float chamber 2 through a passage 16 formed in the body 1, said passage terminating in an annular groove 17 surrounding the Venturi tube 6. Said Venturi tube is provided with an annular series of small perforations 18 through which the liquid issues, in the form of spray, into the mixing chamber 5 The liquid fuel passage 16 is preferably provided with any well known form of strainer, indicated at 19, and witha rotary valve 20, actuated by an arm 21 which is connected by a link 22 with the arm 23 of the throttle valve .9,'so that the liquid fuel is controlled, by

is secured to the top of the chamber '25, preferably by threaded connection 28. A guide 29, in which the valve stem 11 operates, extends through said chambers and 27. A valve housing extends upwardly from the top of the upper chamber 27', and contains three spaced disks 31, 32, and 33. each having a central aperture formed with a valve seat. The stem 11 extends through the two lower disks or seat members '31 and 32, and is provided with valve heads 34 and '35-, the head 34 "controlling the aperture 31 of the lowest disk 31, and the head controlling the apertures 32 and 33 ot the two upper disks 32 and 33 respec tive-ly.

A suction pipe 36, connected with the intake manifold .(not shown) of the engine, leads into the space between the two lower disks 3-1 and 32, and said space alsocommu- 'nicates, through the aperture 31, with the upper chamber 27. The space between the two upper'disks '32 and 33 is vented through the aperture 33, and is also connected with -'s aidc'hatmb'er 27 'by a pipe 3'7. A liquid fuel supply pipe38 leads into said upper chamber 27 and a port 39 connects said chamber with the lower chamber '25. I A float o'r flapper valve 40 controls said port to prevent back flow: of either fuel or air, from the chamber 25 into t'h'echa'inbe'r 27. The pipe 15 supplyin'gthe liquid fuel to the float chamber valve 14, leads from the chamber 25, as shown at 4 1.

The operation of the mechanism above described isessentially similar to that of the 'us'ual'so called vacuum tank, except that it is controlled directly by the main carburetor float 10. Whenthr: level of the liquid in the fio'at chamber 2drops below a predetermined point,'the stem 11 is raised from the position shown in Fig. 1, by the'actionot the floa't '10 and the arms '12, thereby opening the valve 14 and the apertures'or ports 31"ar'1tl-32 and closing the vent '33. Thi's'con'nects the stic-'- non line 36 with the upper orsu'ct-ion chamber 27,"c'ausin'g the liquid to be drawn thereiiito from the supply line "38. At the same time, the liquid contained within the lower or supply chamber 25 flows, by gravity, into the flo at'chainber2. When the liquid in said float chamber rises to the desired predetermined level, the stem 11 is lowered to the 'position'sho'wn, closing the valve 14 and the ports 31 and'32' and opening the vent 33. This cuts off the suction li11e-36, a1'1d vents the suction chamber 27 through the pipe 37 and the vent port'33, thereby permitting the liquid to flow from said chamber 27 through the port 39 intothe'supplychamber '25. The operationis them repeated.

The disksor seat members "31, 32 and are preferably adjust-able within the housing 30 to'enable the valve-heads 34 and 35 *properly to cooperate therewith. Any suitable means may be provided for 'adjust-ing said disks, but for purposes of illustration I have shown them screwed into said housing 30, and the upper and lower disks 33 and 31 are shown as provided with means for adjusting their positions by turning them, from the outside. For this purpose said disks are provided with circumferential grooves 42 whose bottoms are formed with worm threads adapted to be engaged by horizontally disposed worms t3 rotatably mounted in the housing 30 and provided with exterior knobs, one of which is shown at 44 in Fig. The valve 14 may also be formed in an adjustable seat member or disk 14 screwed into an extension 45 of the bottom of the float chamber 2. A removable plug 46 is provided to give access tosaid disk 14:, and also to "serve as a drain plr'i'g for the float chamber 2, the pipe 15, and the chambers 25 and '27.

In'order to heat the mixing chamber 5 and the liquid fuel within the float chamber-2, to assist the vaporization of said fuel, I provide a passage 47 within the lower portion of the body 1, said passage having a preferably cylindrical tubular extension 48 rising into the mixing chamber 5 centrally of the Ve'nturi tube 6, Said passage also communicates with a tubular coil 49 surrounding the float 1'0 within 'the'chamber 2. Inlet and outlet connections 50 are provided which the passage stand the coi 1459 mayfhe connected with a suitable source of hot fluid, not shown, such for example as the exhaust m 'a-ni'fold of the engine. Such hot 'fluid, in pas ing through the coil 49, heats the liquid 'fuel within the "iioa t chamber 2, and in passing through the passage 47 and circulating within the tube 48, heats the air entering through the air inlet 3 and the mixture as it passes through the Venturi tube 6; said tube, moreover, providesa h'ot surfaoe upon which the jets of li u'idfuel'tssuing 'fr omthe apertures 18 impinge, thereby assisting the 'vaporization of said fuel.

An auxiliary air inlet '51-, Figs. 2 and 3, ma be provided in the side e f um body 1 for admitting-air to the mixing chamber "5 in greater quantit than can be supplied-by the inlet 3 and the restrict d position (if the Venturi tube 6, such auxiliaryair inlet being well known in "the art. I prefer to control 'said auxiliary air i'nle'tby a plurality offinterconne'cted shutters '52, each havingan arm 53, and all said arms being "pivdtaill y co'n- 'ne'c'ted with a suitable operating rodj54.

It will be seen from the foregoingthat my device, incorporates in the carburetor itself the functions usually performed by a s'epa rate so-called vacuum tank, such tunetiuns being controlled directly by the carburetor float 10 and its'stein 11. It will also be unilerstood that iny'device cjan readily be applied to an existing carburetor merely by sub-ea 'tuting tlre ch ambers 2 5 and 27' for-the usual cover of the float chamber 2, and by substituting a new stem 11 for the usual needle valve stem associated with the float.

Having thus described my invention what I claim as new and desire to protect by Letters Patent of the United States is 1. A self feeding carburetor comprising a body having a. mixing chamber and a communicating float chamber; a pair of receptacles associated with said floatchamber, one having a liquid inlet and a suction connection and the other having a liquid inlet leading from the first mentioned receptacle and a liquid outlet leading to said float chamber; a float within said float chamber; and means operated by said float for con: trolling said suction connection and said liquid outlet.

2. A self feeding carburetor comprising a body having a mixing chamber and a communicating float chamber; a pair of receptacles associated with said float chamber, one having a liquid inlet, a vent, and a suction connection, and the other having a liquid inlet leading from the first mentioned receptacle and a liquid outlet leading to said float chamber; means for preventing back flow of liquid from the second to the first receptacle; 3. float within said float chamber; and means operated by said float for controlling said suction connection, said vent, and said liquid outlet.

3. A self feeding carburetor comprising a body having a mixing chamber; a float chamber communicating therewith, and a liquid supply chamber positioned above said float chamber, said supply chamber having a liquid inlet, a suction connection, and a liquid outlet leading to said float chamber, a float within said float chamber, a valve stem operated by said float and extending movably through said float chamber and said supply chamber; valve heads carried by said stem for controlling said suction connection and said liquid outlet; seat members with which said valve heads cooperate; and means for separately adjusting the positions of said seat members.

4. A self feeding carburetor comprising a body having a mixing chamber, a float chamber communicating therewith, and a liquid supply chamber positioned above said float chamber, said supply chamber having a liquid inlet, a suction connection, a vent, and a liquid outlet leading to said float chamber; aligned tubular housings extending respectively from the bottom of said float chamber and the top of said supply chamber; valve seat members mounted in said housings for independent vertical adjustment; a movable stem provided with valve faces adapted to cooperate with said seat members to control said suction connection, said vent, and said liquid outlet; and a float within said float chamber for operating said stem.

5. In a carburetor having a float chamber and a float therewithin, a receptacle adapted to be secured to the upper'end of said float chamber and having a liquid supply chamber communicating therewith; asecond receptacle adapted to be secured to the upper end of the first receptacle and having a suction chamber provided with a liquid inlet, a suction connection, and a liquid outlet leading to said supply chamber; and means operated by said float for controlling said suction connection and the feeding of liquid from said; supply chamber to said float chamber.

In testimony whereof I have signed my name to this specification.

HOWARD E. MARSH. 

